Locking device for locking shafts against rotation



Jan. 1, 1952 F. DE HOFFMANN LOCKING DEVICE FOR LOCKING SHAFTS AGAINSTROTATION- Filed Dec. 22, 1947 1 N VE NTOR Fe lp'oc: de H ffnzarmATTORNEY Patented Jan. 1, 1952 uf i,

' Lo'eKINa DEYICEFOR LooKmasnAr-Ts; f

AGAlNST ROTATION" i' y FellinideHoffmann;,BizenosAires; Argentina;

' Application n eembeizz, 19.41, serial No. 193,113,

' InJAIfgflntin'a,Septeinben12;,19f4l 12 1 The; presentinvention referto a locking arrangement applicable to rotating shatts-andsimi lar;elements, its main: obj ect: being; to -provid'e a device" of" the typespecified which, owing't'o its excellent structuralandfuntional features,oifers obviousadvantages" overall-other devices-and ap paratuswhich;witli the' same-era similar purpose, havebeen proposed and usedtodatekThe object o-f'.the-present* inventionbe advantageously-adapted toseveraTpur-poses, such as; for example-fixing in any position-the tuningcentral shaft of' ara-dio-receiving apparatusy so to limit receptiontocertain stations; I as-in the embodimentof the invention,alt-hou'ghfiirgeneral' the same may bapplied tothe purpose ofiinmobilizing a control shaftofany mechanism ormachine;- 1 f I Theinvention likewisecontemplates other-ac cessory object's' that will" bemade clear in the course of the presen d scription...

In order that'theinventioirmaybe clearly understood: and readily putinto. efiectg, same; will now be described with references tirthegacoomepanying drawing, illustrating preferred embodiments of same and inwhiclii Figure- 1 is a diametral sect-ion of the-locking deviceg iirone-ofits preferred embodiments:

Figure-=2 is afront view ot't-he lock drum-, as

key:

FignreB, anothercl-iametr-a-l section, shows a variatiomof the samedevice and; finally Figure-ideapartial-diametral seetionillustratlnganother modificationof thedevice.

well as the inlet opening for the-corresponding Like numerals representlike or similar parts throughout the several figures of the drawing.

In the embodiment shown in Figure 1, the device according to the presentinvention comprises mainly a tubular base I, provided with a flange 2;inside of this tubular base I a cylindrical body 3 is rotatable foradjustment, having as an integral part knob 4, this latter element, andits extension, being provided with a bore 5 which is of cylindricalsection and runs partially through said knob and its prolongation, in anaxial direction.

Said cylindrical body 3 is closed at its free end by a bottom portion 6into which a tubular bushing 1 i threadedly or otherwise secured. Thistubular bushing is capable of being coupled to shaft 8 (provided for thetuning control of a radio-receiving apparatus) by means of a cotter orsimilar arrangement 9.

From the figure it can be seen, furthermore, that a cylindrical bushingI0 is fixedly adjusted to the inside portion of bore 5. This bushing I0I SiaClaimsz. (circa-21:6):

i's closied at its-top end-I Iiand -isgfinturn interiorlyprovid'ed,byscrews or sirnilar'means 12,:wi-t disc it the" lower -face oi WhicIihas agrecessi 1 Beneathsaid disclfi ai'rotatableidise I5 is ar ranged;theinternal face of which is provided witn slctsl"6- in which areheuseesmau s tem's onprojections I1; provided at tli'e -ends 1 (ii -latchesIt? respectively, said-latches being capableof wtight fittingdisplacement withinradial slotswhichex tend through body-3" and-internalbushing- I'll;-v so as themes notches l9 'provided atpropriatepointsoftubu1ar base4; v FromFigures 1'a nd 2 ;it*can be seen;further: more, that-top l 'i' 'of tubularbushing NI; a'swell asfixeddnternal disc l3; are centrally provided with Der-fora'ti' 'onsZi'i from which two: 'radi'al slotss 20 runinoppo's-ited-ireotions forthe r ception of radial leaves ZFoia key 2 2 untilisuehleaves-lodgewithin recess i l-of said fised' diswas is shown: -indetail 'in Figure 1If preferred? rota-ting disc" 5 may-beprovided with a stem zs axianyextendmg fromthe-outer face of same-and serving te guidesaid keyfl.

The device as described is fiiied through screws or similar -m'eans 21 itothe front panei fi of "the corresponding radio-receiving apparatus inthese cond'itions is" coupled to tubular mum-m of' tuning controlshaft-8' by-'-m'eans of 'acotter-pin or similararranglement f 9 in 'suclimanne'ii that? the-turning motion manuallyimpartw to knob 4 willlbetransmitted directly to saidlshaf t If at any given momentit bedesiredito -fix said shaft 8' in: a' certain-: positiona in ordertoalimit reception to.- any one'-receiving station, key- 2215is': insertedand made to pass through bores 20 and radial slots 28' until reachingthe position shown in Figure 1. Thus placed, said hey is turned, so thatleaves 2| of same collide against similar leaves or projections 26provided on the upper face of movable disc I5, thus causing this lattermember to turn, whereby eccentric slots 16, by teeth or projections ll,will bring about the outward displacement of latches I8 which, onentering slots or notches I9 of tubular base I, as is shown in Figure 1,will effectively prevent the assembly from rotating, until such a timeas said latches are again drawn inwardly by operation of thecorresponding key 22.

By suitable arrangement of recesses [9 at certain points in tubular baseI, shaft 8 can be fixed in any one of several predetermined positions,according to the transmitting stations it be desired to select.

The modification shown in Figure 3 is based on the fact that internalbushing lll having a.

top Ila is in this case slideably mounted within bore 5 and is pushedoutwardly by spring 21 pressure-adjusted within a widened portion 28provided in the extension, said outward displacement being limited by akey 29 slideably adjusted in a, slot or notch 29' which extends throughslideable bushing 10.

In this modified embodiment of the invention, internal bushing I isprovided with a bottom wedge portion 30 to which the end of a guide stem23a can be threaded, said stem being capable of exerting a wedge actionagainst heads 3! of respective latches 32 capable of adjustment withinkeeper recesses l9 provided in tubular base I and which normally are:drawn inwardly by springs 33. a

In order to put this device in an operating position, it is notnecessary to use key 22, it being merely required to push in slideablebushing I 0, counteracting the force exerted by spring 21. End 30 ofsaid bushing, acting after the manner of a wedge, will thereby pressagainst heads 3! of latches 32, causing same to be displaced radiallyand outwardly, being thus locked in the recesses IQ of base I and thuspreventing, as in the former case, any later rotation by shaft 8. Duringthis advancing movement of slideable bushing l0, latches 18a will enterrespective notches 34 provided in heads 31, thus preventing the returnmovement of said bushing [I through spring action exerted by member: 21.

In order to unlock the mechanism, key 22 is operated so as to turnmovable disc l5 and thus drag inwardly latches l8a, causing them toleave slots 34 and; allowing bushing 10, to be displaced outwardlybyspring 21 until again occupying the position indicated in Figurefi.Simultaneously, springs 33 displace latches 32 inwardly, caus ing themto leave slots I9 of tubularbushing I and thus perfectly unlocking themechanism.

:The variation shown in Figure 4 resides in the fact that key 22 isequipped with a side leaf 2! notched and cut in agreement withequivalent notches and cuts provided within tubular bushing 13', their,exact coincidence being the only manner in which the key may be turned,said bushing being internally provided with a lengthwise slot 13' thepurpose of which is to allow key. 22 to be inserted in its operativeposition.

The invention as described may be clearly understood, and no furtherexplanations will be required by those versed in thermatter.

Itis evident that various modifications as to build and detail may beintroduced without thereby departing from the essential nature of thisinvention, as clearly defined in the following claims.

I claim:

1. A locking device for control shafts and the like, comprising, atubular base having at least one keeper recess opening through theinterior surface thereof, a knob rotatable inthe base and having shaftcoupling means at its inner end, latch means mounted in the knob forradial movement thereof and in a certain angular position of the knobadapted to be projected into the keeper, said latch means normallyspring urged inwardly to a position substantially flush with theperipheral surface of the knob, a bushing slidable axially inthe knoband spring urged outwardly to a predetermined position, said bushinghaving a key opening in its outer end, a wedge formation at the innerend of the bushing and cooperating with the first latch means to pushthe same into said keeper recess when the bushing is pushed inwardly, tolock the knob to the base plate means rotatable within the bushing andincluding eccentric guide means, second latch means having portionsengaged by said guide means, and movable transversely of the bushingupon rotation of the plate means adapted to en.- gage the first latchmeans when the bushing is pushed inwardly and thereby hold the bushingin an inwardly disposed position. I

2. The device according to claim 1 and wherein the first latch means hasat its inner end at least one notch receiving the second latch means onaxial inward movement of the bushing."

3. The device according to claim 1 and wherein the inner end portion ofthe bushing carries a guide for the key and the plate means has anaperture for the key guide.

FELIX or: HOFFMANN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENI'S Number Name Date 614,732 Leseman et a1 Nov. 22,1898 956,759 Clouse May'3, 1910 1,402,104 SQSS Jan. 3, 1922 1,477,342Gates Dec. 11, 1923 1,586,246 Kirchner et al May 25; 1926 2,117,203 MuroMay 10, 1938 2,226,499 Ledin T Dec. 24, 1940 2,291,217 Hoecker July28,1942

